Insulating and/or dust cover for switches



Jam-12, 1965 c. l. CARLING INSULATING AND/OR DUST COVER FOR SWITCHES Filed Oct. 20, 1961 INVENTOR (aw/4.0 Cmez vc;

ATTO EY United States Patent 3,165,574 INSULATING AND/0R DUST COVER FOR SWITCHES Conrad I. Carling, Hartford, Conn., assignor to Carling Electric, Inc, West Hartford, Conn., a corporation of Connecticut Filed Oct. 20, 1961, Ser. No. 146,587 7 Claims. (Cl. 174-59) This invention relates to electric switches, and more particularly to means for protecting the terminal connections of switches.

The purpose of the present invention is to provide a cover for exposed terminal lugs on switch cases, said cover not only serving as insulating protection for said terminals, but also providing protection against dust, grime, orgrease, which would otherwise contaminate the wire lead connections to said terminal lugs.

A salient feature of the invention is the provision of an insulating or dust cover molded or otherwise formed of insulating material and having a pair of resilient flanges or claws that releasably engage corresponding projecting ends of terminal lugs that are mounted on the switch case. Utilization is made of portions of the terminal lugs to serve as attaching means for the dust cover, the substance of which 'also serves to provide insulation for said lugs. By forming the integral flanges or claws of somewhat resilient material, the cover is connected to the switch case by a simple snap action. Also, the cover may be readily removed by the flexure of one of the flanges from the corresponding terminal lug with which it is engaged.

The particular structure and function of the switch cover herein provides for the quick and easy on-the-site installation and rewiring of switch cases and alteration in circuitry thereof when necessary.

Further provision ismade for a slot in the dust or insulation cover through which the lead wires connected to the switch are laced, so that when the dust cover is temporarily removed for rewiring of the switch cases, the cover will ride along the lead wires and will remain at hand for replacement upon the switch case after the work is done.

Still other objects and advantages of the invention will be apparent from the specification.

The features of novelty whichare believed to be characteristic of the invention are set forth herein and will best be understood, both as to their fundamental prin- FIG. ,2 is a greatly enlarged side view of the switch .case shownin FIG. 1, with the dust cover arranged in an intermediate position .While it is being applied .to the switch case;

FIG. 3 is a fragmentary view of the switch case similar to FIG. 2, showing the dust orinsulating coverin its final secured position on the switch ease;

FIG. 4 is a view, taken on line 44 of FIG. 3, partly in section and partly in dotted outline;

FIG. 5 is a greatly enlarged fragmentary section view, taken on the line 55 of FIG. 4;

FIG. 6 is a greatly enlarged, fragmentary bottom view of a portion of the switch case showing the manner in which the terminal lugs are incorporated thereon; and

FIG. 7 is an enlarged, perspective view of the insulating and/ or dust cover of the present invention.

Patented Jan. 12, T965 a pair of side walls 22, a pair of end walls 23, and a floor 24. The open top of the case is enclosed by a metal plate 25, each end of whichhas an integral downwardly extending leaf 26 which terminates in inwardly extending fingers 27 which engage shoulders 28 in end walls 23 to secure plate 25 to said case.

Connected to top plate '25 is a bushing 31 whose bore communicates with the interior of the ease by way of an aperture, not shown, in plate 25,. Mounted slidably in bushing 31 is a plunger 32 which is connected operatively to various circuit switching elements (not shown) in the interior of case 21.

Positioned ,in floor 24 of case 21 are two sets of electrically conductive circuit studs A, B, C and X, Y, Z, respectively, which extend through said floor and are connected to the various circuit switching elements inside said case. Connected by riveting or the-like, to the bottom portions of studs A and X at one end of case 21 are terminal lugs 35 and36, respectively, and to the bottom portions of studs C and Z at the other end of said case are connected terminal lugs 37 and 38, respectively. Terminal lugs 35, 36, 37 and 38' are made of suitable electrically conductive material such as brass, or the like, and lie flush within respective recesses 41, 42, 4'3 and 44 in the bottom surface of floor 24. Connected to studs A, B, C, and X, Y, Z, by soldering or the like, are insulation covered lead wires 51, '52, 53, 54, 55, 56, respectively, which in turn, are connected to various circuits which are to be controlled by the switch.

All of the lead lines, 51 through 56, are aligned in close parallel array and extend longitudinally from one end of case 21, as shown in FIGS. 1 and 4. In other embodiments, less than six lead lines may be connected to respective circuit studs in case 21 in accordance with the number of circuits the switch is intended to control.

It will be noted, from the illustrations of FIGS. 1-45, that terminal lugs 35, 36, 37 and 38 are somewhat longer than their respective recesses, and, hence, their outer ends extend beyond the end walls of case 21. In the embodiment shown in the drawing herein, the outer protruding edges of said terminal lugs are arrayed substantially parallel to the respectively end walls of the bottom shortened portion of the case. FIGS. 1, 4 and 6.

In order to protect the terminal connections of the lead wires to the studs on thebottom of case 21, there is provided an insulation or dust cover, generally designated 61, which is molded or otherwise fabricated of an insulating material, such as nylon, Bakelite, or the like, in a rectangular, shallow box-like shape. Cover 61 has a pair of end walls 62 and a pair of side walls 63, formed integrally with a floor 64. One end wall 62 has a laterally extending slot 66 through which lead wires 51 through 56 slidably extend.

Each end wall has an upwardly extending integralflange 67 and 68, respectively, whose widths are substantially coextensive with said walls. Flanges 67 and 68each have inwardly inclining slopes'71 and 72, which terminate in inwardly extending elongated claws 73 and 74, respectively. The bottoms of claws 73 and 74 are bounded by laterally extending recesses 75 and 76, respectively.

In order to apply the insulating or dust cover 61 to switch case 21, wires 51-56, which have been soldered to their respective terminals, are first laced as a group through slots 66 (FIG. 1). Thereafter, cover 61 is slid along the group of wires until claw 71 of flange 67 is brought into engagement with terminal lugs 35 and 36, the protruding ends of which enter into recess 75 (FIG. 5). Thereafter, pressure is applied to the bottom of cover 61 in the region of flange 6% to urge the latter upwardly into a position'where claw '74 interlocks with-terminal lugs 37 and 38, the ends of which enter into recess 76 (FIG. 3).

*lange 68 has suflicient resilience whereby it yields outwardly while the ends of terminal lugs 37 and 3:8 slide along slope 72 until claw 74 snaps back into locking engagement therewith.

When cover 61 is locked in position on case 21, as shown in FIG. 3, protection against dust and contamination and against physical and electrical damage is provided for the soldered connections of the lead wires to circuit studs A, B, C, and X, Y, Z. Cover 61 is readily removed from case 21 by inserting the end of a screw driver bit, or the like, above flange 68 and prying it gently whereby it yields outwardly to release the ends of terminal lugs 37 and 38.

It will be noted that when cover 61 is locked in position, its flanges 67 and 68 completely enclose and guard the exposed ends of electrically conductive lugs 35, 36, and 37, 38, respectively.

By providing an easily applied and readily removable insulation cover, the electrical trade can be furnished with switch cases which are adaptable by the electrician for varied switching functions at the installation site. For example, in the embodiment shown in the drawing herein, studs A, B, C, may be selectively wired to control one or two electrical circuits, while studs X, Y, Z, may be selectively wired to control one or two additional circuits. Hence, the single switch assembly may be wired, as desired, to control from one to four circuits. This arrangement permits the standardization of switch case 21 and its versatile adaptability at the installation site for different switch purposes and circuit functions. By providing a self-locking, but readily removable, insulation and dust protector, as embodied in cover 61, alterations in circuit control by the switch can readily be made on the installation site by removing wires from, or connecting them to, studs A, B, C, and X, Y, Z.

In some embodiments wire leads may be attached to the terminal lugs on the bottom of case 21 in such a manner that they extend therefrom in one or more directions other than shown in the figures of the drawing herein. In such event, slot 75 might be omitted and one or more other suitable apertures 81, 82 (FIG. 7) would be provided as required in either or both side walls 63 and floor 64, respectively, of cover 61, to accommodate said leads singly or grouped, without altering the snapon characteristics of flanges 67 and 68 for securing said cover to the switch case.

It is claimed:

1. A switch assembly comprising a case made of insulating material, a plurality of electrically conductive terminals on the bottom of said case, the outer ends of said terminals extending beyond the respective edges of said case, a lead wire connected to at least some of said terminals and extending in a group from one side of said case, a removable cover for said case, said cover releasably engaging said terminal ends by snap action, a slot in said cover, said wires being laced through said slot, said case being movable along said wires when released from said terminals.

2. A switch assembly comprising a rectangular case made of insulating material,"a plurality of electrically conductive terminals on the bottom of said case, at least one of said terminals protruding beyond one end wall of said case, at least another of said terminals protruding beyond the opposite end wall of said case, a removable cover for the bottom of said case, said cover being made of insulating material, an integral flange extending upwardly from each end of said cover, and a claw on each of said flanges, each of said claws resiliently and releasably engaging a respective terminal on opposite ends of said case to secure said cover in position.

3. A switch assembly comprising a rectangular case made of insulating material, a plurality of electrically conductive terminals on the bottom of said case, at least one of said terminals protruding beyond one end wall of said case, at least another of said terminals protruding beyond the opposite end wall of said case, a removable box-like cover for enclosing the bottom of said case, said cover being made of insulating material, an integral flange extending upwardly from each end of said cover, each of said flanges releasably and resiliently engaging a respective terminal on opposite ends of said case to secure said cover in position.

4. A switch assembly according to claim 3, and further comprising a plurality of wires, each of said wires being connected to a respective terminal on the bottom of said case, a slot in one end wall of said cover, said wires being laced through said slot whereby said cover may be moved along said wires to and from a position where said cover releasably engages the bottom of said case for protecting the connections between said wires and their respective terminals.

5. A switch assembly according to claim 3, and further comprising a plurality of wires, each of said wires being connected to a respective terminal on the bottom of said case, at least one slot in said cover, said wires being laced through said slot whereby said cover may be moved along said wires toward and from a position where said cover releasably engages the bottom of said case.

6. A switch assembly according to claim 3, and further comprising a plurality of wires, each of said Wires being connected to a respective terminal on the bottom of said case, a plurality of slots in said cover, said wires being laced through respective slots whereby said cover may be moved along said wires toward and from a position where said cover releasably engages the bottom of said case.

7. A switch assembly comprising a case, a plurality of electrically conductive terminals on the bottom of said case, the outer end of at least one of said terminals extending beyond one wall of said case, the outer end of at least another one of said terminals extending beyond the References Cited by the Examiner UNITED STATES PATENTS 2,665,353 *1/54 Popp 200 16s 2,740,001 3/56 Vergilio et al 174-49 X 3,125,629

3/64 Taylor l74-53 JOHN F. BURNS, Primary Examiner.

ROBERT K. SCHAEFER, Examiner. 

1. A SWITCH ASSEMBLY COMPRISING A CASE MADE OF INSULATING MATERIAL, A PLURALITY OF ELECTRICALLY CONDUCTIVE TERMINALS ON THE BOTTOM OF SAID CASE, THE OUTER ENDS OF SAID TERMINALS EXTENDING BEYOND THE RESPECTIVE EDGES OF SAID CASE, A LEAD WIRE CONNECTED TO AT LEAST SOME OF SAID TERMINALS AND EXTENDING IN A GROUP FROM ONE SIDE OF SAID CASE, A REMOVABLE COVER FOR SAID CASE, SAID COVER RELEASABLY ENGAGING SAID TERMINAL ENDS BY SNAP ACTION, A SLOT IN SAID COVER, SAID WIRES BEING LACED THROUGH SAID SLOT, SAID CASE BEING MOVABLE ALONG SAID WIRES WHEN RELEASED FROM SAID TERMINALS. 